Attitudes and perceptions of high school career and technical education in California\u27s Central Valley

The purpose of this study was to investigate and analyze the attitudes and perceptions of community college leadership, union officials and high school school-to-career counselors regarding high school vocational education in the California\u27s Central San Joaquin Valley, and to identify characteristics deemed most necessary in the design of a high school vocational education program. This researcher investigated this problem using the following questions as guides: 1. What are the attitudes/perceptions of community college leaders, union officials and high school school-to-career counselors, regarding high school vocational education in California\u27s Central San Joaquin Valley? 2. How do the attitudes/perceptions of community college leaders, union officials and high school school-to-career counselors, with and without prior work related experience, compare regarding high school vocational education in California\u27s Central San Joaquin Valley? 3. What characteristics do community college leaders, union officials and high school school-to-career counselors deem most important in the design of a high school vocational education program in California\u27s Central San Joaquin Valley? The design of this study was descriptive in nature and survey in methodology. Specifically, this study utilized 2 written questionairres with rating scales. One questionnaire evaluates attitudes/perceptions regarding vocational education in the Central San Joaquin Valley of California. The other questionnaire evaluates the importance of vocational education program design characteristics. The first survey, the IVE, contained 28 questions. The second survey contained 21 close-ended statements. Both surveys were rated on a 5 point Likert scale. Study findings suggest that community college leaders, union officials and high school counselors collectively view vocational education in California\u27s Central San Joaquin Valley in a positive light. Respondents in all 3 subgroups identified access to further education and training, employer involvement and curriculum alignment with local labor market to be the characteristics most needed in the design of a program to serve students of California\u27s Central San Joaquin Valley

Nonpolar resistive switching in Cu/SiC/Au non-volatile resistive memory devices

Amorphous silicon carbide (a-SiC) based resistive memory (RM) Cu/a-SiC/Au devices were fabricated and their resistive switching characteristics investigated. All four possible modes of nonpolar resistive switching were achieved with ON/OFF ratio in the range 10 6-10 8. Detailed current-voltage I-V characteristics analysis suggests that the conduction mechanism in low resistance state is due to the formation of metallic filaments. Schottky emission is proven to be the dominant conduction mechanism in high resistance state which results from the Schottky contacts between the metal electrodes and SiC. ON/OFF ratios exceeding 10 7 over 10 years were also predicted from state retention characterizations. These results suggest promising application potentials for Cu/a-SiC/Au RM

Specific lid-base contacts in the 26s proteasome control the conformational switching required for substrate degradation.

The 26S proteasome is essential for proteostasis and the regulation of vital processes through ATP-dependent degradation of ubiquitinated substrates. To accomplish the multi-step degradation process, the proteasomes regulatory particle, consisting of lid and base subcomplexes, undergoes major conformational changes whose origin is unknown. Investigating the Saccharomyces cerevisiae proteasome, we found that peripheral interactions between the lid subunit Rpn5 and the base AAA+ ATPase ring are important for stabilizing the substrate-engagement-competent state and coordinating the conformational switch to processing states upon substrate engagement. Disrupting these interactions perturbs the conformational equilibrium and interferes with degradation initiation, while later processing steps remain unaffected. Similar defects in early degradation steps are observed when eliminating hydrolysis in the ATPase subunit Rpt6, whose nucleotide state seems to control proteasome conformational transitions. These results provide important insight into interaction networks that coordinate conformational changes with various stages of degradation, and how modulators of conformational equilibria may influence substrate turnover

Rayleigh-wave dispersion curve: a proxy for site effect estimation?

One of the open issues on the effects of surface geology regards the estimation of site response when limited resources are available. In that restrictive context, one solution is to use soil characteristics as proxy. Despite its extensive use, the most common proxy, Vs30, is presently criticized because it cannot carry alone the main physics of site response. We propose here a statistical investigation of the capabilities of another proxy, the Rayleigh-wave dispersion curve, DC. When considered over a broad enough frequency band, it can provide deeper information missing in the single Vs30 parameter. A set of shear-wave velocity profiles measured for more than 600 Japanese KiK-net stations is used to compute theoretical dispersion curves (DC) and theoretical SH transfer functions (SH), while instrumental surface/downhole spectral ratios were calculated in a previous work (Cadet et al., 2011a). Canonical correlation techniques are applied to this large data set to analyze the relationship between DC and theoretical or empirical site responses. The results indicate very encouraging qualitative statistical relationships between DC and site amplification for numerically derived SH transfer functions, showing significant canonical couples with correlations up to 0.95. Results for instrumental surface/downhole transfer functions correspond to lower correlations (up to 0.73) but still allow the development of quantitative relationships

Mesa-type patterns in the one-dimensional Brusselator and their stability

The Brusselator is a generic reaction-diffusion model for a tri-molecular chemical reaction. We consider the case when the input and output reactions are slow. In this limit, we show the existence of $K$-periodic, spatially bi-stable structures, \emph{mesas}, and study their stability. Using singular perturbation techniques, we find a threshold for the stability of $K$ mesas. This threshold occurs in the regime where the exponentially small tails of the localized structures start to interact. By comparing our results with Turing analysis, we show that in the generic case, a Turing instability is followed by a slow coarsening process whereby logarithmically many mesas are annihilated before the system reaches a steady equilibrium state. We also study a ``breather''-type instability of a mesa, which occurs due to a Hopf bifurcation. Full numerical simulations are shown to confirm the analytical results.Comment: to appear, Physica

Chromospheric seismology above sunspot umbrae

The acoustic resonator is an important model for explaining the three-minute oscillations in the chromosphere above sunspot umbrae. The steep temperature gradients at the photosphere and transition region provide the cavity for the acoustic resonator, which allows waves to be both partially transmitted and partially reflected. In this paper, a new method of estimating the size and temperature profile of the chromospheric cavity above a sunspot umbra is developed. The magnetic field above umbrae is modelled numerically in 1.5D with slow magnetoacoustic wave trains travelling along magnetic fieldlines. Resonances are driven by applying the random noise of three different colours---white, pink and brown---as small velocity perturbations to the upper convection zone. Energy escapes the resonating cavity and generates wave trains moving into the corona. Line of sight (LOS) integration is also performed to determine the observable spectra through SDO/AIA. The numerical results show that the gradient of the coronal spectra is directly correlated with the chromosperic temperature configuration. As the chromospheric cavity size increases, the spectral gradient becomes shallower. When LOS integrations is performed, the resulting spectra demonstrate a broadband of excited frequencies that is correlated with the chromospheric cavity size. The broadband of excited frequencies becomes narrower as the chromospheric cavity size increases. These two results provide a potentially useful diagnostic for the chromospheric temperature profile by considering coronal velocity oscillations

Wave propagation and shock formation in different magnetic structures

Velocity oscillations "measured" simultaneously at the photosphere and the chromosphere -from time series of spectropolarimetric data in the 10830 A region- of different solar magnetic features allow us to study the properties of wave propagation as a function of the magnetic flux of the structure (i.e. two different-sized sunspots, a tiny pore and a facular region). While photospheric oscillations have similar characteristics everywhere, oscillations measured at chromospheric heights show different amplitudes, frequencies and stages of shock development depending on the observed magnetic feature. The analysis of the power and the phase spectra, together with simple theoretical modeling, lead to a series of results concerning wave propagation within the range of heights of this study. We find that, while the atmospheric cut-off frequency and the propagation properties of the different oscillating modes depend on the magnetic feature, in all the cases the power that reaches the high chromosphere above the atmospheric cut-off comes directly from the photosphere by means of linear vertical wave propagation rather than from non-linear interaction of modes.Comment: Accepted for publication in The Astrophysical Journal. 29 pages, 9 figures, 12pt, preprin

Statistical investigation of site ef f ects with emphasis on sedimentary basins, using earthquake and ambient noise recordings

During the last two decades, three empirical methods for assessing site effects have been widely used: the Standard Spectral Ratio (SSR), the Horizontal-to-Vertical Spectral Ratio from earthquake recordings (HVSR) and the Horizontal-to-Vertical Spectral Ratio from ambient noise recordings (HVN). The SSR is considered the reference empirical method to detect amplification as a function of frequency, while the HVSR and the HVN realistically indicate fundamental frequency but, for the majority of the worldwide examined sites, they cannot give reliable amplification curves as a function of frequency. Given the fact that HVSR and especially HVN can be easily obtained, it is challenging to search for any correlation with SSR amplification functions. We used recordings from 168 sites worldwide, for which all three types of spectral ratios were homogeneously processed (Haghsenas et al., Bull. Earthquake Eng. 2008). On this data set we applied standard multivariate statistical analyses, namely, factor analysis and canonical correlation, to investigate and quantify -where it is possible- any correlation between spectral ratios for a certain number of the examined frequency bins. Results show that the correlation between HVN and HVSR is very good. Moreover, their correlation with broad band SSR can be statistically quantified and receive a satisfactory physical explanation. In addition, we looked for the correlation of SSR, HVSR and HVN collected in sedimentary basins (a subset of the previous database) with geometrical and geophysical parameters. T hese attempts were constrained by the limited amount of reliable in-situ data. Among many, we select 5 parameters: Vs30, Hb, Vs_average/Hb, Hb/W_valley, Hb/W_edge (where Hb is the bedrock’s depth below the station; Vs_average is the average Vs from surface to bedrock; W_valley is 2D-width of the valley; W_edge is the distance from the closest valley’s edge). T he analysis assesses that larger are the first 4 parameters, larger is the low-frequency amplification in HVSR and HVN, and lower the high-frequency contribution. Although additional data would improve our statistical investigation and better establish quantitative correlation between spectral ratios and geophysical or/and geometrical characteristics of sedimentary basins, our results clearly show that statistical correlation between SSR and HVN-HVSR is present and modulated in specific frequency domains. T his study has been performed in the framework of the T oK IT SAK-GR EC project (2006-2010)

Gestão de acervos digitais : um estudo a partir das coleções de depoimentos do Museu da Pessoa (SP) e Memorial da Resistência (SP)

A presente pesquisa parte do pressuposto que as rápidas transformações tecnológicas, impulsionadas pelas novas Tecnologias da Comunicação e Informação, estão gradualmente transformando a Museologia de forma que observamos a ascensão do fenômeno dos museus virtuais, instituições que podem existir exclusivamente na internet ou como correspondência de um acervo físico no ciberespaço. Entende-se que estes processos museológicos relacionados à digitalidade fazem parte da Cibermuseologia, corrente da Museologia que estuda as relações cibernéticas estabelecidas nos processos de musealização. Neste sentido, o objetivo deste estudo foi compreender a documentação e preservação de coleções de entrevistas publicizadas no ciberespaço por instituições museológicas com presença virtual, a partir das coleções de depoimentos do Museu da Pessoa (SP) e Memorial da Resistência (SP). A análise dos processos de documentação foi realizada a partir de metodologia quanti qualitativa com o mapeamento e análise dos metadados utilizados pelas instituições através da aplicação de questionários semi-estruturados. Os conceitos que fundamentaram a pesquisa foram os de Museu Virtual, Cibermuseologia, Objeto Digital e Metadado, a partir, principalmente, das abordagens de autores como Henriques (2018), Magaldi (2010), Leschenko (2015), Padilha (2018) e Alves (2010). O diagnóstico realizado gerou uma perspectiva das atuais práticas empregadas por museus virtuais na gestão de acervos digitais, evidenciando processos inerentes a acervos coletados através da história oral, mas também questões singulares quanto a publicização no ciberespaço, como a da estrutura tecnológica demandada neste processo, capacitação profissional e principalmente a contextualização do indivíduo que compartilha suas memórias, de modo que foi observado a atenção que as instituições empregam durante o processo de documentação em assimilar informações referentes ao depoente.The present research is based on the assumption that the rapid technological transformations, driven by the new Communication and Information Technologies, are gradually transforming Museology in a way that we observe the rise of the phenomenon of virtual museums, institutions that can exist exclusively on the internet or as a correspondence of a physical collection in cyberspace. It is understood that these museological processes related to digitality are part of Cybermuseology, a current of Museology that studies the cybernetic relations established in the musealization processes. In this sense, the objective of this study was to understand the documentation and preservation of collections of interviews published in cyberspace by museological institutions with virtual presence, based on the testimonial collections of the Museu da Pessoa (SP) and Memorial da Resistência (SP). The analysis of the documentation processes was carried out based on a quantitative and qualitative methodology with the mapping and analysis of the metadata used by the institutions through the application of semi-structured questionnaires. The concepts that supported the research were those of Virtual Museum, Cybermuseology, Digital Object and Metadata, based mainly on the approaches of authors such as Henriques (2018), Magaldi (2010), Leschenko (2015), Padilha (2018) and Alves (2010). The diagnosis carried out generated a perspective of the current practices employed by virtual museums in the management of digital collections, highlighting processes inherent to collections collected through oral history, but also unique questions regarding publicity in cyberspace, such as the technological structure demanded in this process, training professional and mainly the contextualization of the individual who shares his memories, so that the attention that the institutions employ during the documentation process in assimilating information regarding the deponent was observed